1. Field of the Invention
The present invention relates to a communication device carrying out contactless wireless communication in proximity to an antenna of a counterpart device and a communication method that communicates with the communication device.
2. Description of the Related Art
In recent years, a variety of devices carrying out contactless wireless communication, by moving a fixed device and a portable device in proximity, between both devices has been put into practical use. For example, such devices are widespread that wirelessly communicates by preparing an instrument, such as a contactless IC card or a wireless tag, as a portable device in proximity to a reader, which is a fixed device.
In a case of applications for contactless IC cards, wireless tags, and the like, a reader antenna is configured relatively largely and a card or a tag is moved in proximity to a range in which wireless communication with the reader antenna is allowed, thereby enabling wireless communication. Such a range allowing wireless communication may be considered to be within several centimeters from the reader antenna, for example. The configuration of carrying out contactless wireless communication enables to eliminate a restriction of plug and unplug frequencies in such a case of mounting a portable device, such as an IC card having a terminal in the past, to the fixed device via a connector and to improve usability of the portable device.
Meanwhile, in a case of considering such contactless wireless communication efficiently at high speed of, for example, several or more Gbps, it is considered that a plurality of antennas is respectively disposed in each device and contactless wireless communication is carried out between respective antennas separately to communicate in parallel between the plurality of wireless communication systems. Such high speed contactless proximity wireless communication is applied to data transmission between a variety of information processing devices and peripheral devices thereof, thereby enabling system construction that is free from a restriction of plug and unplug frequencies, such as in a case of connecting peripheral devices with a connector or the like, and allows frequent attachment and removal.
In addition, such devices are put into practical use that can communicate wirelessly even in a situation distant to some extent or can transmit data with another instrument by building a wireless communication unit, such as a wireless LAN, in respective devices separate from the process of contactless wireless communication by moving two devices in proximity. Normally, in a case of loading a plurality of wireless communication functions in one instrument, respective wireless communication functions are activated independently and there is no relationship with conditions of activating other wireless communication functions.
Japanese Unexamined Patent Application Publication No. 2005-115511 discloses an example of carrying out contactless wireless communication between instruments in proximity. Japanese Unexamined Patent Application Publication No. 2007-149475 discloses a technique for hot plugging in a case of high speed transmission on a wired transmission channel between a plurality of instruments.